As regards the Lex Salica, originally the solidus was probably of the Imperial standard, because the Merovingian kings at first in their coinage copied the Imperial coins both in type and weight. And before they issued a coinage of their own they made use of Imperial coins, both gold and silver. Numismatists point in illustration of this to the fact that in the tomb of Childeric at Tournay were found no Frankish coins, but a large number of Roman coins, gold and silver, of dates from A.D. 408 to those of the contemporary Emperor Leo I. (457-474). And for proof that these Roman coins were afterwards imitated by Merovingian princes M. Maurice Prou had only to refer the student ‘to every page’ of his catalogue of ‘Les Monnaies Mérovingiennes.’[126]
The denarius of the Salic law first the scripulum and then the Merovingian silver tremissis of 28·8 w.g.
Now, if the gold solidus was at first of 96 wheat-grains, then the denarius (one fortieth) would be 2·4 wheat-grains of gold, and at a ratio of 1:10 the denarius would be the scripulum of 24 wheat-grains of silver, which was called by early metrologists the ‘denarius Gallicus.’ Further, at 1:12 the denarius would become the Merovingian silver tremissis of 28·8. So that probably the denarius of the Lex Salica may originally have been the scripulum, and under later Merovingian kings their own silver tremissis. Thus these silver tremisses had probably been regarded as the denarius of the Lex Salica for a century or two at least before Charlemagne’s changes.
Up to this time, therefore, there was apparently a distinct connection between the reckoning and figures of the Lex Salica and the actual Frankish coinage. The Merovingian coinage of gold and silver tremisses of 28·8 wheat-grains was therefore, from this point of view, so to speak, a tribal coinage for the Franks themselves, but not one adapted for currency, over a world-wide Empire such as Charlemagne had in view, and with which at last, when adopting the title of Emperor, he had practically to deal.
The changes he made in the currency were intimately connected, not only in time but in policy, with the extension of his kingdom and his ultimate assumption of the Imperial title.
Charlemagne, on conquest of Italy, raised the gold and silver tremissis to the Imperial standard of 32 w.g.
His raising of the weight of the Frankish gold tremissis and silver denarius from the Merovingian standard of 28·8 to the Imperial standard of 32 wheat-grains was probably the result of his conquest of Italy. He seems to have arranged it with the Pope, for they issued silver denarii of the higher standard with the impress of both their names upon them.[127]
It was natural that he should wish his coinage to obtain currency throughout his dominions, and this could not be expected if it was continued at a lower standard than that of the Byzantine Emperor.
Not only in the currency, but also in other matters, extended empire involved the breaking down of tribal peculiarities and greater uniformity in legal provisions and practice.
The Lex Salica still in force for Franks. And its family holdings not yet extinct.